const getHeight = {
  //滚动条在Y轴上的滚动距离
  getScrollTop: function() {
    var scrollTop = 0,
      bodyScrollTop = 0,
      documentScrollTop = 0;
    if (document.body) {
      bodyScrollTop = document.body.scrollTop;
    }
    if (document.documentElement) {
      documentScrollTop = document.documentElement.scrollTop;
    }
    scrollTop =
      bodyScrollTop - documentScrollTop > 0 ? bodyScrollTop : documentScrollTop;
    return scrollTop;
  },
  //文档的总高度
  getScrollHeight: function() {
    var scrollHeight = 0,
      bodyScrollHeight = 0,
      documentScrollHeight = 0;
    if (document.body) {
      bodyScrollHeight = document.body.scrollHeight;
    }
    if (document.documentElement) {
      documentScrollHeight = document.documentElement.scrollHeight;
    }
    scrollHeight =
      bodyScrollHeight - documentScrollHeight > 0
        ? bodyScrollHeight
        : documentScrollHeight;
    return scrollHeight;
  },
  //浏览器视口的高度
  getWindowHeight: function() {
    var windowHeight = 0;
    if (document.compatMode == "CSS1Compat") {
      windowHeight = document.documentElement.clientHeight;
    } else {
      windowHeight = document.body.clientHeight;
    }
    return windowHeight;
  }
};
export default getHeight
